We’re all aware of the limits that the menopause places on female fertility, but we’re perhaps less concerned with what happens to male fertility past middle age.
With movie stars Al Pacino and Robert de Niro welcoming children at 83 and 79, respectively, it’s easy to assume that age is no barrier to becoming a father. (The official record stands at 92.) But is it that straightforward?
Why are fathers older than they used to be?
The age that people become parents has been steadily rising since the mid-seventies and is now at an all-time high, with the average age for fathers at 34 years, compared to 31 years for mothers.
As male parents are most often dependent on female partners – usually of a similar age – to conceive, this rise applies to men as much as it does to women. But as fertility specialist Sarah Martins Da Silva from the University of Dundee notes, the reasons why parents – of any sex – keep getting older are complicated.
“I think there’s a bigger socioeconomic discussion around that and it is obviously to do with the economy, provision of childcare and people not being so financially stable,” she says.
What happens to men’s fertility as they age?
Whilst women have a finite number of eggs in their ovaries, putting a lid on when they can conceive a child, men can continue making sperm indefinitely.
Male fertility does drop off with age, but it’s more of a gradual slip, Martins da Silva says, than during the female menopause. The drop-off is due at least partly to lower levels of hormones; testosterone, for example, is thought to decrease by as much as 1-2 per cent per year after age 30.
One large study, though, suggests that, past 40, levels may vary more from person to person but on average they don’t continue dropping.
Meanwhile, sperm numbers and quality do slowly decrease with age. Sperm quality covers a combination of different factors. For example, sperm cells produced by older men may be poorer swimmers and therefore less likely to reach and fertilise an egg.
Underlying these changes are genetic changes that accumulate during any person’s lifetime and that can’t be avoided or reversed, no matter how much you try to live a healthy life.
The upshot is that whilst it’s still imminently possible for an older man to father a child, it won’t necessarily be as straightforward as it would be for a younger man.
So, can someone become a father at any age?
Theoretically, yes, given that it only takes one healthy sperm to fertilise an egg. According to Martins da Silva, there’s “no cut-off point” at any stage.
“There are people in the press in their seventies and eighties who are fathering children,” she says. “And it shouldn’t be a particular surprise to us that men are still able to do that, because the biology is completely different [than in women].”
In many countries, there is also no limit on when a man can access fertility treatment, whereas in the UK, for example, the NHS only routinely offers treatment for women up to age 42.
Are there any risks associated with being an older father?
There are, unfortunately, increased risks for the father and any potential children. A 2020 review looking at the effects of paternal age on miscarriage found that the risk of miscarriage goes up with increasing age, although the effects of female age on pregnancy loss are more pronounced.
For children born to older fathers, there is plenty of evidence to suggest they are at greater risk of a range of different health conditions, which may be connected to genetic mutations stacking up as we age. Heart defects are more common and the risk of psychiatric disorders increases in children with older fathers.
Importantly, however, some conditions that are more likely to occur are very rare in the general population, meaning that even when the risk is increased it remains pretty low. One risk that many children with older fathers face, though, is their father dying when they are still young and any impacts that may have.
“They tend to do a lot worse in terms of social development, school progress and so on,” says Martens da Silva. “But it’s often in a situation where there’s lots of financial hardship as well.”
Can we learn anything from Pacino though?
The rich and famous are not your typical older fathers. Most of us don’t make the kind of money that Pacino and DeNiro do, so we can’t really relate to the circumstances that they’re bringing children into or the decisions they make about fatherhood. Celebrity-level earnings could help, for example, to cancel out the financial impact of losing a parent at a young age.
On the other hand, ageing celebrities becoming fathers might help highlight the issue of male fertility, which is valuable because, as Martens da Silva points out, it’s an issue that’s given frustratingly little attention.
“I think, generally, men and fertility isn’t a conversation that happens in sex education in schools, or in life.”
About our expert, Dr Sarah Martins Da Silva
Sarah is a clinical reader at the University of Dundee's School of Medicine, where she researches reproductive medicine.
Her work has been published in the Journal Of Assisted Reproduction And Genetics, Human Reproduction and Reproductive Medicine.
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